Abstract
The orphan G protein-coupled receptor GPR17 was shown to be involved in myelin repair and has been proposed as a novel drug target for the treatment of brain and spinal cord injury and for multiple sclerosis. Recently, 3-(2-carboxy-4,6-dichloro-indol-3-yl)propionic acid (MDL29,951, 1a) was discovered and characterized as a potent synthetic GPR17 agonist. In the present study we substantially optimized the preparation of 1a, which is carried out via Japp-Klingemann condensation of 3,5-dichlorophenyldiazonium chloride and deprotonated 2-(ethoxycarbonyl)cyclopentanone yielding phenylhydrazone derivative 5a followed by Fischer indole (diaza-Cope) rearrangement. A robust synthesis of 1a (75% yield) was developed to allow upscaling of the procedure. The developed method was applied to the synthesis of a series of 10 derivatives, eight of which represent new compounds. Biological evaluation in calcium mobilization assays using 1321N1-astrocytoma cells recombinantly expressing the human GPR17 provided first insights into their structure-activity relationships. 3-(2-Carboxy-4,6-dibromo-indol-3-yl)propionic acid (1b) showed similar potency to 1a and represents the most potent synthetic GPR17 agonist described to date with an EC50 value of 202 nM.
Original language | English |
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Pages (from-to) | 86-92 |
Number of pages | 7 |
Journal | MedChemComm |
Volume | 5 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2014 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Medicine
- Pharmacology
- Pharmaceutical Science
- Drug Discovery
- Organic Chemistry